Preheat the oven to 350°F (175°C) and line a cupcake pan with 24 cupcake liners.

In a stand mixer or large mixing bowl, cream together the white sugar and unsalted butter until light and fluffy, about 3-5 minutes.

Add in the large eggs, milk, and pure vanilla extract to the mixture and beat on low until well mixed and smooth, about 2 minutes.

Whisk together the all-purpose flour, baking powder, and salt in a separate bowl. Gradually add this dry mixture to the wet ingredients, alternating with the champagne, mixing just until combined, about 1-2 minutes.

If desired, incorporate the pink food coloring into the batter until evenly distributed. Fill each cupcake liner about two-thirds full with the batter.

Bake in the preheated oven for 14-17 minutes or until they spring back when touched or a toothpick inserted comes out clean.

Remove from the oven and let cool in the pan for 5 minutes before transferring to a wire rack to cool completely.

For the frosting, simmer champagne in a saucepan over medium heat until reduced by half. Allow to cool. Cream softened unsalted butter and confectioners’ sugar in a bowl, then gradually add the cooled champagne to achieve a smooth frosting.

Frost each cooled cupcake with the champagne buttercream and sprinkle with decorative sprinkles.